1. Field of the Invention
The present invention relates to an electric motor. In particular, the present invention relates to a motor used in a disk drive apparatus or a fan.
2. Description of the Related Art
In a motor 80 disclosed in FIG. 22 of JP-A 2008-283759, a housing 32 is supported by a mounting plate 34b. The mounting plate 34b includes a plate-shaped portion 341b, an attachment portion 342b, and an adjustment portion 343. The adjustment portion 343 is defined between the plate-shaped portion 341b and the attachment portion 342b. The attachment portion 342b is defined by fluing performed upward in an axial direction.
A spindle motor described in US 2011/0084575 includes a base plate 400 including a reverse burring part 500. The reverse burring part 500 includes a core support part 510 and a burring hole 520. The core support part 510 includes a round part 512 and a core contact part 514. A burring part 522 of the reverse burring part 500 is arranged to extend downward. A bearing housing 300 is joined to the burring part 522.
JP-A 2000-166171 discloses a small-sized motor. The small-sized motor includes a core holder 25. The core holder 25 is arranged to hold a stator core 5 with portions of the core holder 25 holding the stator core 5 from both sides in an axial direction. The core holder 25 is fixed to an outer circumference of a bearing holder 3 by an elastic force.
In the case of the motor illustrated in FIG. 22 of JP-A 2008-283759, once the housing 32 is press fitted and thereby fixed to the mounting plate 34b, the housing 32 is held by only a small region of an inner circumferential surface of the mounting plate 34b through press fit. Therefore, the housing 32 tends to be easily tilted, and designing a mechanism to prevent a tilt of a rotation axis may be difficult depending on specifications of the motor.
In the spindle motor described in US 2011/0084575, both an inner circumferential surface and an outer circumferential surface of a bearing 200 radially overlap with a fixing range over which the burring part 522 is fixed to the bearing housing 300, and the inner circumferential surface of the bearing 200 tends to be easily deformed by press fitting of the bearing housing 300 to the burring part 522. Moreover, a lower end of the burring part 522 is arranged at a level higher than that of a lower end of the bearing housing 300, and secure support of the bearing housing 300 is not achieved.